Idle dips

[Xepa27]

Hey all,

I've been experiencing an unusual problem lately with my '97 GS500e, essentially when warmed up (or cold) when I pull the clutch the rpms will drop and sit around 800rpm or less and may stall. I have my idle set around 1500 rpm and have adjusted the pilot screw to run a bit rich, so I'll have to turn it back a quarter turn. The idle will sit around 1500 rpm but I'm only able to get it there if I ride the bike at low speed, otherwise it wants to sit at the aforementioned 800-1000 rpms with an eventual increase to 1500(read long). If I adjust the idle screw any more I have a hanging idle around 2500rpm, if I turn it back the bike straight up stalls when pulling the clutch.

The bike works perfectly fine when rolling and I usually just give the bike a bit of throttle to prevent stalling.

Has anyone experienced these kinds of issues before?

[mr72]

I would guess the pilot air passage is clogged, or the pilot jet is clogged, or both. The fact that you "set" the idle to 1500 tells me that the pilot air passage is probably clogged, since you opened the throttle plate to compensate, then you wound up enriching the pilot to provide more fuel when being mixed with all the extra air coming in across the throttle.

I'd pull the carbs, clean the pilot air passage and replace the pilot jets. While it's apart might as well clean everything else, replace the o-rings, etc. All the regular stuff.

[Xepa27]

I rebuilt the carbs this winter and changed the pilot jet and everything was fine at the beginning of the season, I commute to work with the bike, so it is used regularly. I could take a look at cleaning the jets as it's easy enough but at the same time it's hard for me to believe they'd be clogged so fast while being used regularly. The interior of the tank is in good shape as well.

[mr72]

did you clean the pilot air passages? Also did you replace the o-rings on the pilot needles?

Given your description I would have to think the pilot is probably way too rich, your idle is set too high at 1500, you say you get hanging idle if you lean it more, I'd say lean it to where you can get the idle to run properly at 1100-1200 with the throttle stop backed all the way out and see what happens then.

Something's not right, but it could be a half dozen things. The 1500 idle speed is a sure sign that something is wrong and you are compensating for it.

IMHO.

[Xepa27]

It was cleaned and the O-rings were changed, I'll play with the pilot screw tonight and clean the carb top to bottom over the weekend and see if there are any changes.

[qcbaker]

How does the bike idle in neutral? Are you certain that the idle dip is not just the clutch not fully disengaging?

[Xepa27]

I'll double check the free play, good call.